First, you're redeclaring a Vector everytime, which is not correct. Every Vector created is then eligible for the garbage collector, but you could create just one to optimize your code and save memory. You should do this instead.

Now, to solve your issue, you should first make sure your SQL request returns the result you want by executing it out of the Java program (PhpMyAdmin for example). If the result is correct, please show us the output of your Java program. Does it look like: